Horizon Zero Dawn contains an incredibly solid combat system. Aloy will be equipped with 2 main weapon categories. Melee and ranged. Your melee weapons will comprise of spears and other primitive weapons used for raw damage. Ranged weapons are usually bows, slings and if you are lucky something with a little more fire power.
The combat system is based on top of a stealth engine. All enemies will be unaware of your presence until they spot you. This allows you to bypass enemies, take them out 1 by 1 or just run in and kill everyone John Wick style.
Ranged Or Melee?
At the start of the game, you will have fairly limited moves when it comes to combat, but it will be enough to help you determine what you prefer. I would suggest you specialize, but not too heavily. You can specialize in the form of skill points. Spending these will unlock special abilities and moves that will greatly influence the direction you go. Stealth and ranged combat is a safe way to play. It is slow, but highly effective. All out melee attack is also effective, but will result in a lot of deaths, particularly early on in the game. A lot of enemies can charge and kill you before you know what hit you. I much prefer the ranged/stealth approach for this reason. The decision is up to you. Be sure to study the skill tree to know what you are in for.
I will go into greater detail in a sub category for this as stealth is a fairly big aspect of this game. The game adopts an approach of being hidden until spotted. Once spotted the combat will be triggered. Some enemies are passive and will run from you, others are aggressive and will immediately try to kill you on sight. When it comes to humans and robots, there will be a white question mark ? above their head. Yellow means they are alerted to something and red means they have spotted you.